This invention relates to a means for assuring discrete pin alignment in a cathode ray tube-base assembly and more particularly to improved means for achieving alignment of at least one CRT pin spatially encompassed within a substantially tubular isolation component of the associated base member.
Noteworthy achievement in cathode ray tube technology, in particular the tube types employed in color television receivers has resulted in the development of compact electron gun structures evidencing greater efficiencies. These compact guns, being oriented within tube envelope neck portions of reduced diameter, have the necessary operating voltages for the various elements thereof (heaters, cathodes, accelerating and focusing electrodes, etc.) supplied via an annular array of connector pins sealed into and projecting from the stem closure portion of the tube. As the neck diameter of the tube envelopes become smaller, the spacing between the connector pins likewise decreases.
Prior art tubes have evidenced large voltage differentials between certain of the pins in the connector array. This differential, sometimes in the order of 5KV to 12KV, has necessitated the incorporation of some form of arc protection into the tube base and socket combination. Base and socket means have been designed in the art to minimize inter-pin arcing wherein at least one of the vulnerable high voltage pins is tubularly encompassed by one or more spatially related isolation structures integrally formed as part of the base member. In conjunction therewith, a compatible socket member has receiving means to mate with the respective tubularly encompassed pin, thereby effecting an isolated high voltage connection. This type of protective connection was found to be very beneficial.
To prevent the isolated pin from being bent out of alignment during tube basing or as a result of subsequent tube mishandling, a pin aligning insert has been devised for positioning within the pin accommodating tubulation. The body member of this insert means has a longitudinal bore therein to protectively encompass the pin during tube basing and thereby prevent its being bent. Desirably, this protective insert is retained within the base during the period between tube basing and ultimate usage. But, due to the interplay of manufacturing tolerances and thermal contractions and expansions, the inserts are not always engaged within the tubular structure to the degree desired. Consequently, in certain instances, bumping of the tube during shipment or storage may cause the protective insert to become disengaged.